Security and remote access for vehicular safety and convenience systems

ABSTRACT

A security system in a vehicle extends its protection to installed equipment of the vehicle, such as audio components and navigation systems. The installed equipment is armed and disarmed by the security system remote control, preventing the equipment from normal functioning after unauthorized removal. The security system further enables programming, monitoring, and diagnosing of the installed equipment through the security system remote control.

REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.11/018,689, filed on Dec. 20, 2004, which is incorporated herein byreference in its entirety, and to which priority is claimed.

FIELD OF THE INVENTION

The present invention relates generally to security systems, and, moreparticularly, to security systems installed in automobiles and othermobile environments.

BACKGROUND

A modern automobile is a technological marvel of substantial economicvalue.

Often, it is protected by a security system designed to prevent theftand vandalism. The security system is just one of the optional equipmentitems present in a typical automobile or another vehicle. There are manyothers, for example, high-performance stereo sound reproduction systems,rear-seat entertainment systems, and navigation systems. These systemsand similar entertainment, safety, and convenience items typicallyinstalled in cars and other vehicles (“installed equipment” or“installed components” hereinafter) can account for a considerable partof the total value of the vehicle. Left in the vehicle, the installedequipment is subject not only to the danger of being stolen togetherwith the vehicle, but also to its own vagaries: for example, theinstalled equipment can be stolen from the vehicle, or the equipment canbe abused while the vehicle is entrusted to a third party, such as amechanic or a parking attendant.

Consider, for example, a high-power audio amplifier. Its cost can be inmany hundreds or thousands of dollars, and much effort can be spent onits installation. Obviously, it presents a tempting target to apotential thief. Furthermore, the power produced by the amplifier candamage the loudspeakers of the vehicle under some circumstances. Thevehicle's owner may not want to allow access to the amplifier and to therest of the sound reproduction system when leaving the vehicle with aparking attendant or an auto mechanic. For these and other reasons, someamplifiers have a mode in which they are non-functional. When locked inthis mode, the amplifier cannot be used in the vehicle where it wasoriginally installed or in another environment, without a key used tounlock it. Unfortunately, inserting and removing a physical key, such asa key that includes an electronic memory with burned-in code, isinconvenient because the amplifier is likely to be located in a trunk oranother location that is not conveniently accessible. A need thus existsfor a convenient method and apparatus to lock and unlock installedequipment electronically.

Moreover, the installed equipment may need to be configured,periodically monitored, and diagnosed. The stereo amplifier discussedabove, for example, can be a rather sophisticated piece of audioequipment with programmable configuration and diagnostic features. Oneexample of such features is the availability of programmable gainadjustment and gain adjustment lockout mechanisms. Another example isthe programmability of turn-on delay. Yet another example is theavailability of self-diagnostic information stored within the amplifier.Typically, access to such configuration and diagnostic features requiresspecialized equipment used by dealers and installers of electronicequipment. It would be desirable to provide at least limited access tothese features to the end-user, and to dealers and installers withoutthe specialized equipment. A need thus exists for a method and apparatusthat would allow convenient access to configuration and diagnosticfeatures of the installed equipment.

SUMMARY

The present invention is directed to apparatus and methods that satisfythese needs. An embodiment of the invention herein disclosed provides acombination of a security system and an installed equipment item. Thesecurity system includes a base controller installed in a vehicle, abase transceiver installed in the vehicle and coupled to the basecontroller, and a remote control. The remote control includes a humaninput device, such as a keypad, a display device, for example, a screen,and a remote control transceiver for communicating with the basetransceiver and an installed equipment device. A person can use theremote control to send instructions and data, which are inputted throughthe human input device, to the base controller, via the base and remotecontrol transceivers. Instructions and data can also be sent directly tothe installed equipment item via the remote control and from theinstalled equipment item directly to the remote control.

A bus couples the base controller to the installed equipment item. Theinstalled equipment item performs some function in the vehicle,typically a function related to safety, convenience, entertainment, orsecurity. Examples of the installed equipment items include audiocomponents, such as speakers and amplifiers, positioning and locationsystems, and entertainment systems. The remote control is connected tothe installed equipment item via a wireless connection.

The installed equipment item includes an operational memory storingprogram code, a processor executing the code, an interface port couplingthe processor to the bus. The processor prevents the installed equipmentitem from performing the function, audio amplification, for example, ina normal manner after receiving an arm command from the base controllervia the bus. In a similar manner, the remote control itself can be usedto prevent the installed equipment item from performing the function,audio amplification, for example, in a normal manner after receiving anarm command from the remote control via the wireless connection.

The security system can send the arm command in predefinedcircumstances, for example, when the security system is armed to protectthe vehicle. The user can send an arm command via the remote control atany time, whether the security system is armed or disarmed. When thesecurity system is disarmed, the base controller sends a disarm commandto the installed equipment item. When the processor receives the disarmcommand, it returns functionality of the item to normal state. A disarmcommand can also be sent directly to the installed equipment item viathe remote control. A disarm command from the remote control will alsoreturn the functionality of the installed equipment item to the normalstate. If power is removed from the installed equipment item when it isin the armed state, the item will require resetting using either aspecial tool, an installer access code, or a command directly from theremote control before it will function normally again.

The remote control of the security system can also be used to configurethe parameters of the installed equipment item. The parameters, forexample, turn-on delay, gain adjustment range, and audio performanceparameters of an amplifier, are entered through the remote control andsent to the base controller of the security system or directly to theinstalled equipment item. If sent to the base controller, the basecontroller then sends the parameters to the processor of the installedequipment item. Once the processor receives the parameters, itconfigures the installed equipment item in accordance with the receivedparameters.

The remote control can also be used to obtain maintenance and diagnosticdata from the installed equipment item. An operator of the securitysystem uses the remote control to enter an instruction to request thedata, and the remote control sends the instruction either to the basecontroller or directly to the installed equipment item. If sent to thebase controller, the base controller then sends a command to theinstalled equipment item, requesting the data. Once the processorreceives the command, it either sends the requested data to the basecontroller, which, in turn, sends the data back to the remote control,or the processor causes the command to be sent directly to the remotecontrol if the command originated directly from the remote control. Theprocessor can also cause the command to be sent directly to the remotecontrol even if the command did not originate directly from the remotecontrol. The remote control subsequently displays the data on itsdisplay device.

Note that a second installed equipment item can serve as a man-machineinterface used by the operator to enter configuration parameters, torequest and view the maintenance and diagnostic data, or to arm anddisarm the installed equipment of the vehicle. For example, a rear-seatentertainment system can be connected to the security system and set upto send instructions to an audio amplifier, and to receive and displaydata from the amplifier.

These and other features and aspects of the present invention will bebetter understood with reference to the following description, drawings,and appended claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a high-level schematic diagram of a combination of a vehicularsecurity system with an installed equipment item, in accordance with thepresent invention;

FIG. 2 illustrates selected steps of a process performed by theprocessor of the installed equipment item of FIG. 1 in deactivating theinstalled equipment item, in accordance with the present invention;

FIG. 3 illustrates selected steps of a process performed by theprocessor of the installed equipment item of FIG. 1 in activating theinstalled equipment item, in accordance with the present invention;

FIG. 4 illustrates selected steps of another process performed by theprocessor of the installed equipment item of FIG. 1 in activating theinstalled equipment item, in accordance with the present invention;

FIG. 5 is a high-level schematic diagram of a combination of a vehicularsecurity system with a high-performance audio amplifier, in accordancewith the present invention;

FIG. 6 is a high-level schematic diagram of a combination of a vehicularsecurity system, a high-performance audio amplifier, and a rear-seatentertainment system, in accordance with the present invention; and

FIG. 7 illustrates selected steps of a process of issuing a command fromthe rear-seat entertainment system to the high-performance audioamplifier of FIG. 6, in accordance with the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to several embodiments of theinvention that are illustrated in the accompanying drawings. Whereverpossible, same or similar reference numerals are used in the drawingsand the description to refer to the same or like parts. The drawings arein a simplified form and are not to precise scale. For purposes ofconvenience and clarity only, directional terms, such as, top, bottom,left, right, up, down, over, above, below, beneath, rear, and front, maybe used with respect to the accompanying drawings. These and similardirectional terms should not be construed to limit the scope of theinvention in any manner. Furthermore, in descriptions and in claims,“couple,” “connect,” and similar words with their inflectional morphemesdo not necessarily import an immediate or direct connection, but includeconnections through mediate elements within their meanings.

Referring more particularly to the drawings, FIG. 1 illustrates, in ahigh-level schematic diagram form, a combination 10 of a security system100 with an installed equipment item 140. The security system 100 hasthree major components: a remote control 110, a base transceiver 120,and a base controller module 130. The base transceiver 120 and the basecontroller module 130 are installed in a car, while the remote control110 is a portable device designed to allow a person to operate securitysystem 100 or installed equipment item 140 remotely.

In the embodiment illustrated in FIG. 1, the base controller 130performs the logic and interface functions of the security system 100.The base controller 130 includes a base processor 132 coupled to arandom access memory (RAM) 133 and to a read only memory (ROM) 131. TheROM 131 stores the program code executed by the processor 132 and thepreprogrammed data used by the processor 132 in the course of executingthe program code. The ROM 131 may include a programmable ROM (PROM)module, an electrically programmable ROM (EPROM) module, and anelectrically erasable programmable ROM (EEPROM) module. In some variantsof the combination 10, the memory 131 includes an EEPROM device thatalso stores data received from the installed equipment item 140. Thedata is thus preserved through interruptions in electrical power and canbe retrieved in the future for diagnostic and maintenance purposes. TheRAM 133 is a scratch pad memory for storing intermediate results andother temporary data generated by the processor 132 in the course ofexecuting the program code.

The base controller 130 further includes a transceiver interface block125, through which the base controller 130 communicates with thetransceiver 120 and the remote control 110, and input/output (I/O)blocks 137 and 138. The I/O block 137 couples the base processor 132 toinputs 135, which are connected to various sensors and user controls ofthe security system 100, such as a valet switch, vibration sensor,movement sensor, door and trunk status (open/close) sensors, ignitionsensor, and other sensors and controls. The I/O block 138 provides thebase processor 132 with the capability to control various output devicesconnected to outputs 136, such as system status LEDs that indicatewhether the system 100 is on or off, and whether an alarm event hasoccurred since activation of the system. Additionally, the processor 132uses the I/O block 138 to activate the siren of the security system 100.In some variants of the combination 10, the I/O blocks 137 and 138 alsoprovide connections to a battery voltage monitor, trunk releasesolenoid, wireless telephone link, vehicle locator system, relaysoperating power windows, power lock solenoids, and ignition and starteractivation relays used to start the car remotely. Thus, the I/O blocks137 and 138 enable the base controller 130 to receive the inputs thatare needed for or affect the operation of the security system 100, andto operate various indicators and other output devices that are part ofthe security system 100.

Numeral 139 designates an interface block that couples the basecontroller 130 to the installed equipment item 140 via a bus 162. In theparticular embodiment of FIG. 1, the bus 162 includes a serial data bus.Thus, the interface block 139 includes a serial interface port. Moregenerally, variants of the combination 10 in accordance with the presentinvention can use various other connections between the item 140 and thesecurity system 100, including parallel digital buses, analogconnections, optical links, radio frequency (RF) links, infrared links,and other wired and wireless connections. In each case, the interfaceblock 139 takes appropriate form in accordance with the actualconnection used. For example, where the bus 162 is a parallel bus, theblock 139 is a parallel port.

In the combination 10, the base controller 130 is implemented as amicrocontroller, with the processor 132, memories 131 and 133, and I/Oblocks 125, 137, 138, and 139 being fabricated on the same integratedcircuit. In other embodiments, the base controller is implemented as amicroprocessor with the memories and some of the I/O blocks beingphysically located on integrated circuits other than the integratedcircuit containing the microprocessor. While microprocessors andmicrocontrollers represent general-purpose, software-driven digitalstate machines that can be used for performing many functions of thebase controller 130, and of other processors and controllers describedin this document, in some embodiments, these processors are implementedas application-specific digital state machines. These state machines canbe primarily or exclusively hardware-based engines; the state machinescan also combine both hardware and software functions.

Remote control 110 includes a controller 116, a transceiver 1 5, and anantenna 114 that allows the controller 116 to communicate with theantenna 122 on transceiver 120 over a communication link 118 andinstalled equipment item 140 via communication link 119. Communicationslinks 118 and 119 can be parallel digital buses, analog connections,optical links, radio frequency (RF) links, infrared links, and otherwired and wireless connections as would be recognized by one withordinary skill in the art. The remote control 110 further includes analphanumeric display 112, and pushbutton and scroll wheel input devices113 (i.e., human input devices). Using these human interface devices 112and 113, the operator of the security system 100 can send remotecommands to security system 100 and installed equipment item 140, andreceive from system 100 and installed equipment item 140 informationsuch as status, diagnostic, maintenance, and acknowledgement data. Aswill be seen below, the data received by remote control 110 can includeinformation originating in the installed equipment item 140.

The installed equipment item 140 includes an installed equipmentprocessor 144, memory modules 146 and 147, and an interface port 142.The port 142 is similar to the port 139 of the base controller 130 inthat it provides data flow between the base processor 132 and theinstalled equipment processor 144, but port 142 also includes a wirelesstransceiver 143, which can include a built-in antenna, to communicatedirectly with installed equipment item 140. It should be recognized thattransceiver 143 can also occupy its own separate port or location withininstalled equipment item 140. The memory modules 146 include both RAMand ROM modules, while the memory module 147 is a non-volatile,electrically programmable memory module. In the embodiment illustratedin FIG. 1, the non-volatile memory module 147 is an EEPROM. Theprocessor 144 executes program code stored in the memory 146,selectively activating and deactivating normal operation of theinstalled equipment item 140, depending on the value stored in anactivation location within the EEPROM 147. As will be seen, the value inthe activation location can be controlled, directly or indirectly, bythe base controller 130, and also directly by remote control 110.

FIG. 2 illustrates selected steps of a process 200 performed by theprocessor 144 in deactivating the installed equipment item 140.Beginning with step 202, the processor 144 determines whether installedequipment item 140 is in a deactivated state. Processor 144 reads theinformation stored in the activation memory location to see if installedequipment item 140 is in a deactivated state. If installed equipmentitem 140 is in a deactivated state, processor 144 does not need todeactivate installed equipment item 140. Thus, the process ends. Ifinstalled equipment item 140 is not in a deactivated state, thedeactivation process continues to step 204.

At step 204, the processor 144 monitors the status of the serial bus 162through the interface port 142. When the base controller 130 outputsinformation on the serial bus 162, the processor 144 knows the source ofthe information because the base controller outputs a unique identifierassociated with the base controller 130 as part of the information. Thebase controller 130 can do this, for example, by outputting a particularsequence on extra output channels available in the security system 100,which is a multi-channel system. The installed equipment item 140 isprogrammed to recognize the particular sequence of channel numbers asthe unique identifier used by the base controller 130.

The information output by the base controller 130 is generally of twotypes: data and commands. One of the commands from the controller 130 tothe installed equipment item 140 is “Enter Valet Mode.” At step 206, theprocessor 144 determines whether the information on the bus 162 is the“Enter Valet Mode” command. If the command is indeed “Enter Valet Mode,”the processor proceeds to step 208; otherwise, it returns to step 204.At step 208, the processor 144 identifies the source of the “Enter ValetMode” command by reading the unique identifier output by the basecontroller 130. At step 210, the processor 144 stores the identifier ofthe base controller 130 in a memory location of the EEPROM 147; we willdesignate this memory location as the “source of deactivation” location.At step 212, the processor 144 writes an “inactive” value into theactivation location of the EEPROM 147. The processor 144 thendeactivates the installed equipment item 140 at step 214, so thatinstalled equipment item 140 either does not work or its functionalityis reduced or otherwise modified.

FIG. 3 illustrates steps of a process 300 performed by remote control110 in deactivating the installed equipment item 140. Beginning withstep 302, the remote control 110 can directly send a signal to installedequipment item 140 to deactivate installed equipment item 140, withoutregard as to whether installed equipment item 140 was previouslyactivated or deactivated. Then, at step 304, installed equipment item140 sends a signal to processor 144 to cause processor 144 to write an“inactive” value into the activation location of EEPROM 147, thus endingthe process.

FIG. 4 illustrates selected steps of a process 400 performed byprocessor 144 in activating installed equipment item 140. Beginning withstep 402, processor 144 determines whether installed equipment item 140is in an activated state. Processor 144 reads the information stored inthe activation memory location to see if installed equipment item 140 isin an activated state. If installed equipment item 140 is in anactivated state, processor 144 does not need to activate installedequipment item 140. Thus, the process ends. If installed equipment item140 is not in an activated state, the activation process continues tostep 404.

At step 404, Processor 144 monitors the status of bus 162 throughinterface port 142. When activity is detected on bus 162, processor 144reads the information on bus 162 and determines whether the informationincludes an “Exit Valet Mode” command, at step 406. This command directsprocessor 144 to cause installed equipment item 140 to exit the Valet orinactive mode, if certain conditions are met. If the information on bus162 includes the “Exit Valet Mode” command, the processor proceeds tostep 408; otherwise, it returns to step 404. At step 408, processordetermines the source of the “Exit Valet Mode” command from the uniqueidentifier of the source included in the information on the bus 162. Atstep 410, processor 144 compares the unique identifier received and theidentifier stored in the source of deactivation location of EEPROM 147.If the two identifiers do not match, process flow returns to step 404.If the two identifiers do match, processor 144 returns the functionalityof the installed equipment item 140 to normal state, at step 412. Atstep 414, processor 144 writes an “active” value into the activationlocation of EEPROM 147, or simply clears this location. Thus, installedequipment item 140 needs to either receive the Exit Valet Mode commandfrom the base controller that locked it or from remote control 110, inorder to resume normal operation with full functionality.

FIG. 5 illustrates steps of a process 500 performed by remote control110 in activating the installed equipment item 140. Beginning with step502, remote control 110 can directly send a signal to installedequipment item 140 to activate installed equipment item 140, withoutregard as to whether installed equipment item 140 was previouslyactivated or deactivated. Then, at step 504, installed equipment item140 sends a signal to processor 144 to cause processor 144 to write an“active” value into the activation location of EEPROM 147, thus endingthe process.

FIG. 6 illustrates selected steps of a process 600 performed by theprocessor 144 in activating the installed equipment item 140. Process600 is similar to the process 400, but it limits the number ofunsuccessful attempts to return the equipment item 140 to normaloperation from the Valet Mode. By an “unsuccessful attempt” we meanreceiving the Exit Valet Mode command from a source other than the basecontroller that initiated the Valet or inactive mode.

Beginning with step 602, processor 144 determines whether installedequipment item 140 is in an activated state. Processor 144 reads theinformation stored in the activation memory location to see if installedequipment item 140 is in an activated state. If installed equipment item140 is in an activated state, processor 144 does not need to activateinstalled equipment item 140. Thus, the process ends. If installedequipment item 140 is not in an activated state, the activation processcontinues to step 604.

At step 604, processor 144 clears the attempt counter. At step 606,processor 144 monitors the status of the bus 162 through the interfaceport 142. When processor 144 detects activity on bus 162, it reads theinformation on the bus 162 and determines whether the informationincludes an “Exit Valet Mode” command, at step 608. If the informationon bus 162 includes the “Exit Valet Mode” command, processor proceeds tostep 610; otherwise, it returns to step 604. At step 610, processordetermines the source of the “Exit Valet Mode” command from the uniqueidentifier of the source of the command. At step 612, the processor 144compares the unique identifier received and the identifier stored in thesource of deactivation location of the EEPROM 147. If the twoidentifiers match, the processor returns the functionality of theinstalled equipment item 140 to normal state, at step 614, and, at step616, writes an “active” value into the activation location of the EEPROM147, or simply clears this location.

If the two identifiers do not match, processor 144 proceeds to step 618and increments the attempt counter. At step 620, processor 144 comparesthe attempt counter to a limit set on the number of unsuccessfulattempts. If the limit has not been reached, processor 144 returns tostep 604. Otherwise, it proceeds to a security routine at step 622. Inthe process 600, security routine 622 causes the processor to stopmonitoring bus 162 for a predetermined period of time, for example, onehour. This interval helps to defeat brute-force attempts to guess theunique identifier of the base controller that caused installed equipmentitem 140 to enter the Valet Mode.

In some variants of the embodiment illustrated in FIG. 1, the value inthe activation location is modified directly by base controller 130,which performs direct memory access operations to EEPROM 147 throughports 139 and 142, and bus 162.

With regard to the conditions that cause the security system 100 toissue the Enter and Exit Valet Mode commands, in one embodiment, system100 sends the Enter Valet Mode command to installed equipment item 140when the operator sends from remote control 110 an instruction to arminstalled equipment item 140, or to lock and arm the vehicle. Theinstruction may require the operator to input an access code. Similarly,security system 100 sends an Exit Valet Mode command when it receives anunlock/disarm instruction from the operator. The unlock instruction mayalso require the operator to input an access code. System 100 can beconfigured to issue the Enter Valet Mode command whenever the securityfunctions of security system 100 are activated, for example, when thedoors of the car are locked for a predetermined time with the ignitionin the off state, or when an alarm is triggered. System 100 can also beconfigured to issue the Enter Valet Mode command on power-up, so thatinstalled equipment item 140 is in the Valet Mode until the operator ofsystem 100 causes system 100 to issue an Exit Valet Mode command byentering an instruction to disarm the installed equipment item 140,accompanied by the operator's access code.

FIG. 7 illustrates, in a high-level schematic diagram form, acombination 70 of a security system 700 with a high-performance audioamplifier 740. As can be seen, the structure of combination 70 is quitesimilar to the structure of the combination 10 of FIG. 1, with similaror identical components being designated by similar numbers having “7”as the first digit. Amplifier 740 includes an interface port 742, anoperational memory 746, EEPROM module 747, power supply 748, cooling fan750, and display LEDs 751, connected to an amplifier processor 744. Thefunction of port 742 is to provide an interface between a bus 762 andprocessor 744, as well as allow communications between remote control710 and amplifier 740 via link 719. Link 119 can be a parallel digitalbus, analog connection, optical link, radio frequency (RF) link,infrared link, or other wired and wireless connection as would berecognized by one with ordinary skill in the art. Memory 746 serves tostore the code executed by the processor 744, and the variables andother data used by the processor 744 in the course of executing theprogram code, while EEPROM module 547 stores the configuration andsecurity data for amplifier 740, as well as certain diagnostic andmaintenance data that is preserved in the absence of power. Amplifier740 further includes an audio processing section 743, audio inputconnectors 741, and audio output connectors 745. The audio processingsection 743 provides substantially all audio processing functions forthe audio signals received at the connectors 741 and output at theconnectors 745. These functions—such as signal conditioning,equalization, and gain—are controlled by the amplifier processor 744based on values stored in the EEPROM 747. The audio processing section743 includes a digital signal processor.

The following is a high-level description of selected aspects of theoverall functionality of amplifier 740, including some of the functionsof audio processing section 743.

ESP Port. Amplifier 740 has an ESP port for connecting a specialconfiguration and maintenance tool used for configuring the amplifierparameters, such as those described in the following paragraphs, and forreading maintenance and diagnostic data from amplifier 740. An installerof amplifier 740 uses the tool to write the parameters directly intoEEPROM 747. In other embodiments, the tool allows the installer to causeamplifier processor 744 to write the parameters into EEPROM 747.

Base Controller to Amplifier Communications. The base controller 730 ofsecurity system 700 is capable of sending commands to and exchanginginformation with the amplifier 740, using bus 762 and ports 739 and 742.The commands include configuration commands, diagnostic/maintenancecommands, and status queries; the information includes diagnostic,maintenance, configuration, and status data. The base controller 730 cansend commands after receiving an appropriate instruction from the remotecontrol 710, which may be accompanied by an access code (password orpersonal identification code). In some variants of the combination 70,the instruction comes through the configuration and maintenance tool,which is capable of connecting to the base controller 730.

Security Mode. Amplifier 740 can function in three different securitymodes: ESP, PIN, and OFF. In the ESP mode, the amplifier 740 can bearmed, for example, by arming the security system 700, and the amplifier740 will not function until it is disarmed. If main power isdisconnected while the amplifier 740 is armed, the amplifier 740 willhave to be reset using the configuration and maintenance tool, before itwill become functional again. Amplifier 740 enters and exits the armedstate in a way similar to the way installed equipment item 140 of FIG. 1enters and exits the Valet Mode.

The PIN mode is similar to the ESP mode, but amplifier 740 requires aspecial personal identification access code to be transmitted to it viabus 762 to disarm and become functional. In operation, security system700 receives the personal identification code from remote control 710via link 718, together with the instruction that directs security system700 to disarm amplifier 740. Alternatively, a special command sequencecan be sent from security system 700 to amplifier 740, instead of theuser-selectable PIN. The special command sequence can be an installeraccess code, i.e., a code not accessible to general public, butavailable to installers and dealers in security equipment. Basecontroller 730 receives the special security code from remote control710 or from the configuration and maintenance tool.

In the OFF state, the amplifier 740 is not protected by the securitysystem 700.

The security mode of the amplifier is determined by a security modevariable stored in the EEPROM 747, which can be modified by any of themethods described above for modifying configuration variables (e.g.,using the configuration and maintenance tool from the ESP port or from aport of the base controller 730, or issuing an instruction to modify thevariable from the remote control 710).

Turn-On Delay. Turn-on delay of the amplifier is the time betweenapplication of power to the amplifier and the amplifier being turned on.This delay is used to prevent multiple high-power consuming componentsfrom turning on simultaneously and causing the power supply voltage todip excessively, or to spike. The turn on delay can also be used to turnon components so that they are in a known state. The turn-on delay forthe amplifier 740 can be selected from several preprogrammed values, forexample, 0.5, 1.0, 1.5, and 2.0 seconds, or the delay period can be setby the operator or installer. Delay period selection (and otherconfiguration parameters, including those described below) is performed,for example, by issuing from the remote control 710 an instructionaccompanied by an installer access code, or by connecting theconfiguration and maintenance tool to the ESP port of the amplifier 740,or to the base controller 730. The turn-on delay value is stored in theEEPROM 747.

Fan Mode. The amplifier 740 can be programmed for four operational modesof the fan 750: OFF, ON, Amp PWR, and Thermal Control. In the OFF and ONstates, the fan is either on or off at all times, respectively. In theAmp PWR mode, the fan is on whenever the amplifier is turned on. In theThermal Control mode, the processor 744 turns on the fan 750 when thetemperature of the amplifier 740 exceeds a predetermined temperaturelimit. The temperature limit, which is stored in the EEPROM 747, can beselected from several preprogrammed values, or it can be set manually bythe operator or installer from a continuous range of temperatures. Thefan mode is determined by the value of a fan mode variable, also storedin the EEPROM 747.

Output Impedance. The processor 744 sets the output impedance of theamplifier 740 to 2 or 4 ohms, depending on the value of an outputimpedance variable stored in the EEPROM 747.

Load Protection Mode. In the default setting of the Load Protectionmode, the amplifier 740 will not drive a 2 ohm load when it is set tooutput impedance of 4 ohms. The default setting can be overridden,however, by changing the value of a load protection mode variable, whichis stored in the EEPROM 747. When the default protection mode isoverridden, the amplifier will drive a 2 ohm load from a 4 ohm setting,either permanently or for a preprogrammed period, depending on the valueof an override period variable, also stored in the EEPROM 747.

Display Mode. The display mode can be programmed to OFF, Fault Display,and Query Response states. In the OFF state, a subset of the displayLEDs 751 is turned off. In the Fault Display mode, the processor 544causes the display LEDs 751 to flash out codes corresponding to apredetermined number of immediately preceding “trips” of the amplifier740. A “trip” means a set of conditions that caused the amplifier not tofunction. Examples of trip conditions include exceeding a thermal limit,power supply overvoltage, or excessively low load impedance. Theamplifier 740 stores in the EEPROM 747 the trip events for subsequentdiagnostics. In the Query Response state, the LEDs 751 flash outinformation responsive to queries sent by the base controller 730 overthe bus 762. The information can include the trip events. As in the caseof other programmable modes, the display mode setting is stored in theEEPROM 747.

Note that the trip events and other diagnostic and configuration datastored internally in the amplifier 740 can also be read through theconfiguration and maintenance tool pluggable into the ESP port of theamplifier 740, or into the base controller 730.

Input Signal Range Adjustment. Depending on the value of an input signalrange variable (stored in the EEPROM 747), the audio processing section743 is configured for different maximum levels of input signal. (Thepurpose of setting the maximum input signal level is to avoidoverdriving the audio processing section 743, while using the full poweravailable from the amplifier 740. When the input signal falls bellow thelower limit, dynamic range is lost and the amplifier output is less thanthe rated power; when the upper limit is exceeded, the amplifier isoverdriven and its output is distorted.) In one implementation of theamplifier 740, the audio processing section 743 can be configured forfour different maximum input voltage ranges: (1) 0.5-1.0 volts, (2)1.0-2.0 volts, (3) 2.0-4.0 volts, and (4) 4.0-8.0 volts. In anotherimplementation, the maximum input signal range is set by the operator orinstaller from a continuous range of values. The input signal range isstored in the EEPROM 747.

The amplifier 740 also provides the installer with the capability toprevent the operator from choosing an inappropriate input signal range.This is done by setting range adjustment lockout variables, which arestored in the EEPROM 747. The range adjustment lockout variables are setusing the configuration and maintenance tool, or by issuing from theremote control 710 an appropriate instruction accompanied by aninstaller access code.

Gain Adjustment. The amplifier 740 includes a selector that allows theoperator to adjust, within limits, the gain of the amplifier. Gainadjustment variables (stored in the EEPROM 747) determine the adjustmentlimits. Note that the upper and lower gain adjustment limits can both beset to the same value, locking out the manual adjustment capability.Gain adjustment variables are accessible using the configuration andmaintenance tool, or by issuing from the remote control 710 anappropriate instruction accompanied by an installer access code.

Valet Mode Enable. If the Valet Mode is enabled, the security system 700protects the amplifier 740 whenever the security system 740 is in theValet Mode, in accordance with the Security Mode in effect at that time.If the Valet Mode is disabled, the amplifier 740 functions normally whenthe security system 700 is in the Valet Mode. The Valet Mode is enabledby writing an enable value into the valet mode enable variable stored inthe EEPROM 747.

Display Supply Voltage Mode. The power supply 748 monitors the supplyvoltage received by the amplifier 740. A real time or averaged readingof the supply voltage can be output to the ESP port of the amplifier740, or to the remote control 710 (via the bus 762 and the basecontroller 730), in accordance with the value of a display supplyvoltage variable stored in the EEPROM 747. This variable has three validranges: OFF, AUTO, and POLLED. In the OFF state, the amplifier 740 doesnot output the supply voltage reading. In the AUTO state, the supplyvoltage reading is output periodically. The period, also stored in theEEPROM 747, can be selected among several preprogrammed values, or itcan be set manually by the operator or installer from a continuous rangeof allowed values. In the POLLED state, the amplifier 740 outputs thesupply voltage reading in response to a polling command sent from basecontroller 730. The polling command can be initiated by an instructionfrom the remote control 710.

Display Supply Current Mode. The power supply 748 also monitors thepower supply current pulled by the amplifier 740. A real time oraveraged reading of the current can be output to the ESP port, or to theremote control 710, in accordance with the value of a display supplycurrent variable stored in the EEPROM 747. This variable has three validranges: OFF, AUTO, and POLLED. In the OFF state, the amplifier 740 doesnot output the supply current reading. In the AUTO state, the supplycurrent reading is output periodically. The period, also stored in theEEPROM 747, can be selected from among several preprogrammed values, orit can be set manually by the operator or installer from a continuousrange of allowed values. In the POLLED state, the amplifier 740 outputsthe supply current reading in response to a polling command sent fromthe base controller 730, which can be initiated by an instruction fromthe remote control 710.

Display Output Wattage Mode. The amplifier 740 monitors the power of itsaudio output. An averaged reading of the audio power can be output tothe ESP port, or to the remote control 710, in accordance with the valueof a display output wattage variable stored in the EEPROM 747. Thisvariable has three valid ranges: OFF, AUTO, and POLLED. In the OFFstate, the amplifier 740 does not output the audio power reading. In theAUTO state, the output wattage reading is output periodically. Theperiod, also stored in the EEPROM 747, can be selected from severalpreprogrammed values, or it can be set manually by the operator orinstaller from a continuous range of allowed values. In the POLLEDstate, the amplifier 740 outputs the audio power reading in response toa polling command sent from the base controller 730, which can beinitiated by an instruction from the remote control 710.

Setting of Circuit Protection Limits. As has already been mentioned, theamplifier 740 monitors certain parameters, such as input voltage, loadimpedance, and temperature, and shuts itself down when these parametersviolate circuit protection limits of the amplifier 740. The specificcircuit protection limits can be written into the EEPROM 747 using anyof the techniques already described. Because improper settings of thecircuit protection limits can cause permanent damage to the amplifier740, in some variants of the combination 70, modification of the circuitprotection limits requires the use of the configuration and maintenancetool.

Setting of Audio Parameters. Some audio performance parameters of theaudio processing section 743 are also configurable. These parametersinclude, for example, values of time alignment for different audiochannels, enable/disable of surround sound, internal settingscontrolling equalization over multiple bands, enabling sonic effects ofa large concert hall, definitions of artificial sitting positions,crossover frequencies, and many others. In operation, the processor 744configures the audio parameters based on the audio configuration datastored in the EEPROM 747. This is done on power-up and after the audioparameters are modified in the EEPROM 747. To configure the audioprocessing section 743, the processor 744 reads the parameters from theEEPROM 747, and then writes appropriate data into the registers of theaudio processing section 743, for example, into registers of the DSPprocessor of the section 743. The audio configuration parameters can bewritten into the EEPROM 747 by any of the methods already discussed,e.g., using the configuration and maintenance tool connected to the ESPport or to the port in the base controller 730, or by sending theparameters from the remote control 710.

Some functional features described above are absent from certainvariants of the combination 70. And the above list of the functionalfeatures is far from exclusive. For example, some variants of thecombination 70 provide for automatic or polled output by the amplifier740 of its internal temperature, rail voltage, load impedance sensed,and a host of other parameters. As another example, the informationprovided to the ESP port or the remote control 710, such as supplyvoltage, supply current, and output wattage, can be flashed out in codeby the LEDs 751, as was described above with reference to the trips ofthe amplifier 740.

This document describes the inventive devices and methods forprotecting, configuring, maintaining, and diagnosing installedequipment. This is done for illustration purposes only. Neither thespecific embodiments of the invention as a whole, nor those of itsfeatures limit the general principles underlying the invention. Inparticular, the invention is not limited to audio amplifiers, butincludes external crossovers, equalizers, power capacitors, navigationaldevices, airbags, and similar safety, audio, convenience, entertainment,and security devices. The invention is also not limited to automotiveuses. The specific features described herein may be used in someembodiments, but not in others, without departure from the spirit andscope of the invention as set forth. Many additional modifications areintended in the foregoing disclosure, and it will be appreciated bythose of ordinary skill in the art that in some instances some featuresof the invention will be employed in the absence of a corresponding useof other features. The illustrative examples therefore do not define themetes and bounds of the invention and the legal protection afforded theinvention, which function is served by the claims and their equivalents.

1. An installed equipment item for a vehicle, the item performing afunction in the vehicle, the installed equipment item comprising: aninstalled equipment digital state machine controlling the function; andan interface capable of connecting the installed equipment digital statemachine to a vehicle security system remote control via a communicationlink to provide information flow between the installed equipment digitalstate machine and the security system remote control; wherein theinstalled equipment digital state machine prevents the installedequipment item from performing the function normally after receiving anarm command from the security system remote control via the bus.
 2. Theinstalled equipment item of claim 1, wherein the installed equipmentdigital state machine causes the installed equipment item to perform thefunction normally after receiving a disarm command from the securitysystem remote control via the communication link.
 3. The installedequipment item of claim 2 further comprising an operational memorystoring program code, wherein the installed equipment digital statemachine comprises a processor executing the program code.
 4. Theinstalled equipment item of claim 3, wherein an interruption of powerbetween successive arm and disarm commands causes the processor toprevent the item from performing the function normally until the item isconnected to a configuration and maintenance tool and reset by the tool.5. The installed equipment item of claim 3, wherein an interruption ofpower to the installed equipment item between successive arm and disarmcommands causes the processor to prevent the item from performing thefunction normally until the item is reset by receiving an installer codevia the communication link, the installer code not being available togeneral public.
 6. The installed equipment item of claim 3 furthercomprising a non-volatile memory for the purpose of storingconfiguration parameters of the installed equipment item, theconfiguration parameters affecting operation of the installed equipmentitem.
 7. The installed equipment item of claim 6, wherein the programcode causes the processor to store maintenance and diagnostic data ofthe installed equipment item in the non-volatile memory.
 8. Theinstalled equipment item of claim 7, wherein the program code causes theprocessor to send to the security system remote control, via thecommunication link, the maintenance and diagnostic data in response tocommands requesting the maintenance and diagnostic data received by theprocessor from the security system remote control via the communicationlink.
 9. The installed equipment item of claim 7 further comprising anESP port capable of coupling the installed equipment item to aconfiguration and maintenance tool, wherein the program code causes theprocessor to send to the ESP port the maintenance and diagnostic data.10. The installed equipment item of claim 7 further comprising an ESPport capable of coupling the installed equipment item to a configurationand maintenance tool, wherein the program code causes the processor tosend to the ESP port the maintenance and diagnostic data in response tocommands requesting the data received from the security system.
 11. Theinstalled equipment item of claim 7 further comprising an ESP portcapable of coupling the installed equipment item to a configuration andmaintenance tool, wherein the program code causes the processor to sendto the ESP port the maintenance and diagnostic data in response tocommands received through the ESP port.
 12. The installed equipment itemof claim 7, further comprising at least one light emitter coupled to theprocessor, wherein the program code causes the processor to flash codescorresponding to the maintenance and diagnostic data on the at least onelight emitter.
 13. The installed equipment item of claim 7, furthercomprising at least one light emitter coupled to the processor, whereinthe program code causes the processor to flash codes corresponding tothe maintenance and diagnostic data on the at least one light emitter inresponse to commands received from the security system remote control.14. The installed equipment item of claim 7, wherein the security systemremote control comprises a display and an input device for enabling aperson to enter instructions, the instructions comprising at least oneinstruction to send a command requesting the installed equipment item tosend data to the remote control.
 15. The installed equipment item ofclaim 14, wherein the installed equipment item further comprises anaudio amplifier.
 16. The installed equipment item of claim 15, whereinthe data comprises a trip event data of the audio amplifier.
 17. Theinstalled equipment item of claim 3, wherein: the security system remotecontrol comprises a display and an input device for enabling a person toenter instructions, the instructions comprising at least one instructionto send configuration parameters to the installed equipment item. 18.The installed equipment item of claim 17, wherein the installedequipment item further comprises an audio amplifier.
 19. The installedequipment item of claim 18, wherein the configuration parameters includea turn-on delay of the audio amplifier.
 20. The installed equipment itemof claim 18, wherein: the audio amplifier comprises a fan; and theconfiguration parameters include a mode of operation of a fan variablethat determines the mode of operation of the fan.
 21. The installedequipment item of claim 18, wherein the configuration parameters includean output impedance of the audio amplifier.
 22. The installed equipmentitem of claim 18, wherein the configuration parameters include a loadprotection mode variable that determines whether the audio amplifierwill drive a load with impedance lower than output impedance of theaudio amplifier.
 23. The installed equipment item of claim 18 furthercomprising at least one light emitter coupled to the processor, whereinthe configuration parameters include a display mode variable, and theprogram code causes the processor to flash a code associated with a tripevent of the audio amplifier if the display mode variable is set to afirst value.
 24. The installed equipment item of claim 18, wherein theconfiguration parameters include an input signal range adjustmentvariable that sets maximum signal input power for the audio amplifier.25. The installed equipment item of claim 18 further comprising aselector for manual adjustment of gain of the audio amplifier, whereinthe configuration parameters include a gain adjustment variable thatdetermines gain adjustment range of the selector.
 26. The installedequipment item of claim 7 further comprising a navigation systemperforming the function.
 27. The installed equipment item of claim 7further comprising a stereo system performing the function.
 28. Theinstalled equipment item of claim 7 further comprising a rear-seatentertainment system performing the function.
 29. The installedequipment item of claim 7 further comprising an audio amplifierperforming the function.
 30. The installed equipment item of claim 1,wherein the communication link is a wireless communication link.
 31. Aninstalled equipment item for a vehicle, the item performing a functionin the vehicle, the installed equipment item comprising: an operationalmemory storing program code; a processor executing the program code; andan interface capable of connecting the processor to a vehicle securitysystem remote control via a communication link to provide informationflow between the processor and the security system remote control;wherein the processor, in response to a query command received from thesecurity system remote control via the communication link, sends to thesecurity system remote control, via the communication link, datarelating to operation of the installed equipment item.
 32. An installedequipment item according to claim 31, wherein the processor receivesconfiguration parameters for the installed equipment item from thesecurity system remote control via the communication link and configuresthe installed equipment item based on the received configurationparameters.
 33. An installed equipment item according to claim 32,wherein the data relating to operation of the installed equipment itemcomprises maintenance and diagnostic data.
 34. An installed equipmentitem according to claim 32, further comprising a non-volatile memorystoring the received configuration parameters.
 35. An installedequipment item of claim 32, wherein the installed equipment item is anaudio amplifier.
 36. An installed equipment item of claim 35, whereinthe requested data comprises trip event data of the audio amplifier. 37.An installed equipment item according to claim 31, further comprising anon-volatile memory storing the data relating to operation of theinstalled equipment item.
 38. The installed equipment item of claim 31,wherein the communication link is a wireless communication link.
 39. Aninstalled equipment item for a vehicle, the item performing a functionin the vehicle, the installed equipment item comprising: an operationalmemory storing program code; a processor executing the program code; andan interface capable of connecting the processor to a vehicle securitysystem remote control via a communication link to provide informationflow between the processor and the security system remote control;wherein the processor receives configuration parameters for theinstalled equipment item from the security system remote control via thecommunication link and configures the installed equipment item of thereceived configuration parameters.
 40. The installed equipment itemaccording to claim 39, further comprising a non-volatile memory storingthe received configuration parameters.
 41. The installed equipment itemof claim 39, further comprising an audio amplifier, wherein the functioncomprises audio amplification.
 42. The installed equipment item of claim41, wherein the configuration parameters comprise audio performanceparameters of the audio amplifier.
 43. A vehicular system, comprising: asecurity system base controller installed in a vehicle; a securitysystem base transceiver installed in the vehicle and coupled to the basecontroller; a base controller bus and a remote control communicationlink; an installed equipment item for performing a function, theinstalled equipment item being installed in the vehicle and coupled tothe base controller via the base controller bus, the installed equipmentitem comprising an operational memory storing program code, an installedequipment processor executing the code, and an interface port couplingthe installed equipment processor to the base controller bus and theremote control communication link; and a security system remote controlcomprising a human input device, a display device, and a remote controltransceiver communicating with the installed equipment item via theremote control communication link, the remote control being capable ofsending instructions and data inputted through the human input device tothe installed equipment device via the remote control transceiver, theremote control being connected to the remote control communication linkwherein the installed equipment processor prevents the installedequipment item from performing the function normally after receiving anarm command from the remote control via the remote control communicationlink.
 44. The vehicular system of claim 43, wherein the installedequipment processor causes the installed equipment item to perform thefunction normally after receiving a disarm command from the remotecontrol via the remote control communication link.
 45. The vehicularsystem of claim 44, wherein an interruption of power to the installedequipment item between successive arm and disarm commands prevents theitem from performing the function normally until the item is connectedto a configuration and maintenance tool.
 46. The vehicular system ofclaim 44, wherein an interruption of power to the installed equipmentitem between successive arm and disarm commands prevents the item fromperforming the function normally until the item is reset by receiving aninstaller code from the remote control via the remote controlcommunication link, the installer code not being available to generalpublic.
 47. The vehicular system of claim 44, wherein the installedequipment item further comprises a non-volatile memory for storingconfiguration parameters of the installed equipment item, theconfiguration parameters affecting operation of the installed equipmentitem.
 48. The vehicular system of claim 44 further comprising anon-volatile memory, wherein the program code causes the installedequipment processor to store maintenance and diagnostic data of theinstalled equipment item in the non-volatile memory.
 49. A system,comprising: a base controller bus and a remote control communicationlink; a security system base controller installed in a vehicle andcoupled to the base controller bus; a security system base transceiverinstalled in the vehicle and coupled to the base controller; aninstalled equipment item for performing a function, the installedequipment item being installed in the vehicle and coupled to the basecontroller via the base controller bus, the installed equipment itemcomprising an operational memory storing program code, an installedequipment processor executing the code, and an interface port couplingthe installed equipment processor to the base controller bus and theremote control communication link, the installed equipment processorconfiguring the installed equipment item for performing the functionbased on values of configuration parameters; and a security systemremote control comprising a human input device, a display device, and aremote control transceiver communicating with the installed equipmentitem, the security system remote control being capable of sendinginstructions and data inputted through the first human input device tothe installed equipment item wherein the security system remote controlis capable of receiving the configuration parameters through the humaninput device and sending the configuration parameters to the installedequipment item processor via the remote control communication link. 50.The system of claim 49, wherein the installed equipment item furthercomprises an audio amplifier, the function comprises audioamplification, and the configuration parameters comprise audioperformance parameters of the audio amplifier.
 51. A process forsecuring an installed equipment item in a vehicle protected by asecurity system including a remote control, the process comprising thesteps of: sending arm signals from the remote control to the installedequipment item when the security system is disarmed; reducingfunctionality of the installed equipment item in response to the armsignals to prevent normal functionality of the installed equipment item;and returning functionality of the installed equipment item to normal inresponse to receiving disarm signals from the remote control.
 52. Aprocess for configuring an installed equipment item in a vehicleprotected by a security system including a remote control, the processcomprising the steps of: receiving installed equipment itemconfiguration data at the remote control; sending the configuration datafrom the remote control to the installed equipment item; receiving theconfiguration data at the installed equipment item; and configuring theinstalled equipment item based on the configuration data.
 53. A processof obtaining maintenance and diagnostic data from an equipment iteminstalled in a vehicle protected by a security system including a remotecontrol, the process comprising the steps of: sending from the remotecontrol to the installed equipment item an instruction to request thedata from the installed equipment item; receiving the instruction at theinstalled equipment item; sending, in response to the command, the datafrom the installed equipment item to the remote control; receiving thedata at the remote control; and displaying the data at the remotecontrol.